Thread-controlling mechanism for multiple-needle sewing-machines



G. S. GATCHELL. THREAD CONTROLLING MECHANISM FOR MULTIPLE NEEDLE SEWING MACHINES.

- APPLICATION FILED SEPT. 25. I919- Q Patented Nov. 22, 1921.

5 SHEETSSHEET 1.

RN INVENTOR ATTORNEY a; WITNESSES? I G. f

G. S. GATCHELL.

THREAD CONTROLLING MECHANISM FOR MULTIPLE NEEDLE SEWING MACHINE& APPLICATION FILED SEPT. 25,19I9. 1,397,507.

Patented Nov. 22, 1921.

5 $HEETSSHEET 2.

INVENTOR [MW BY A ORNEY G.S.GATCHELL THREAD CONTROLLING MECHANISM FOR MULTIPLE NEEDLE SEWING MACHINES APPLICATION FILED SEPT; 25, I9I9- I 1,397,507. Patented Nov. 22, 1921.

5 SHEETSSHEEI 3.

INVENTOR WITNESSES:

ORNEY G. S. GATCHELL. THREAD CONTROLLING MECHANISM FOR MULTIPLE NEEDLE SEWING MACHINES.

. APPLICATION FILED SEPT. 25. 1919. 4 1,397,507 Patented Nov. 22, 1921.

5 SHEETS-SHEET 4.

INVENTOR A TORNEY G. S. GATCHELL. THREAD CONTROLLING MECHANISM FOR MULTIPLE NEEDLE SEWING MACHINES.

APPLICATION FILED SEPT. 25, I919.

1 397,507,- Patented Nov. 22, 1921..

5 SHEETS-SHEET 5.

INVENTOR lUlttlTEfi ETATES FATENT @FFlQE. i

enonen s. oa ronnnn, or ROSELLE rnnir, newanesinr, nssreivoa a e THE SINGER Iciinnrncrnnme COMPANY, a conronarron on NEW JERSEY Y THREAD-CONTROLLING MECHANISBI FOR MULTIPLE-NEEDLE SE'UfING-MAGHINES.

Application filed September 25, 1919.

.flo all whom it may concern:

Be it known that I, Gnonon S. Givrorlnnr, a citizen of the United States, residing at Roselle Park, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Thread- Uontrolling Mechanisms for liilultiple-lleedle Sewing-lilachines, of which the following is a specification, reference being had therein to, the accompanying drawings.

This invention relates to thread-controlling mechanism for multiple-needle sewing machines, more particularly of the type represented in my copending application Serial No. 185,446, filed August 1.0, 1917, and my United States Patent No. 1,361,247, of December 7, 1920.

In a multipleneedle single-looper machine, wherein the needles are arranged close together, it is necessary to control the needlethreads with a high degree of nicety at certain critical periods of the stitch-forming cycle if high speed operation is to be attained, and in my prior machine I have provided series otrotary thread-controlling cams for closely and individually controlling the needle-threads. By carefully shaping these cams, the desired accuracy of control of the needle-threads can be obtained under a givenset of operating conditions, 2'. e., 1"'or a given stitch-length in work of a given character. When sewing work or". a different character, however, or when the stitch-length is altered, slight changes are introduced in the requirements for perfect needle-thread control and the machine is liable, at times, to produce malformed stitches or break thread under high speed opera-ting conditions.

An object of the present invention therefore, is to provide needle-thread controlling mechanism for multiple-needle machines which will control the needle-threads with a uniform degree or accuracy at the critical periods of the stitch-forming cycle under the various operating conditions to wlnch the machine is likely to be subjected in practice.

llLlOlG particularly, the invention has for an object to provide means in maintaining an even strain or tension upon the needlethread loops which are about the looper at the period of the cycle when the looper is retracting and the descending needle points are about to pass their respective needle- Specification of Letters Patent.

Fat-tented Nov. 22, 1921.

Serial No. 326,290.

loops. If the needle-loops are too tight at this time they will tend to assume positions too far forward on the looper. If too loose, they will be dragged too. far rearwardlyl In other words, if the tension on the needle loops is not very nearly what it should be, the needles are likely to split the thread of or enter their respective previously formed loops instead of passing down beside said loops, as is essential to the formation of perfect stitching.

To the attainment of these ends, I have combined with suitable positively acting take-up means, such, for example, as disclosed in my prior applications, a series of individual yieldingdevices for placing a light drag upon the respective needle-threads at certain periods of the stitch-forming cycle to absorb possible slack thread between the take-ups and the work and to give up thread under a possible abnormal strain. These devices function, together with the take-up means, to maintain a uniform tension on the needle-threads at the critical periods of'th e stitch-forming cycle under all the various operating conditions met with in practice.

In the accompanying drawings, Figure 1 is a side elevation of the machine embodying the invention. Fig. 2 is a top plan view of the forward part of the bracket-arm of the machine. Fig. 3 is a fragmentary side elevation of the parts shown in Fig. ,2 at period of the cycle when the needle-bar is rising. Fig. 4. is a view similar to Fig. 3 at a period of the cycle when the needle-bar is descending. Fig. 5 is a front end elevation of the bracket and work-arms showing the yielding thread-controlling devices; the needle being at the end or its down stroke and the looper being fully retracted. Fig. 6 is a similar view at a slightly later period of the cycle when the needles are rising and the looper has entered well into the first needleloop and is just entering the second needle-- loop. Fig. 7 is a view similar to igs. 5 and 6 but showing the needlebar near the upper end of its stroke and the looper near the end or its advancing stroke. in this figure the needle-threads are shown as released by the yielding thread-controlling devices preparatory to the action of the needle-bar in pulling thread from the supply. Fig. 8 shows the threadcontrolling devices with the needle-bar at the upper end 01" its stroke. Fig; 9 shows the needle-thread under the structed substantially in accordance with the control of the yielding thread-controlling devices as the descending needles are about to pass their respective previously formed loops on the retracting looper; the position being the same as in Fig. 4. Fig. 10 is a detail perspective view of two of the yielding thread-controlling devices arranged on a common support. Fig. 11 is a front elevation of a modified form of yielding threads controlling device and Fig. 12 is a large diagrammatic view of the needle-thread take-up cams with which the present machine is equipped. I g

'In the preferred embodiment'of the in-' vention, as illustrated, the machine is condisclosure of my said eopending applications and comprises a frame formed with a base,

not shown, fromwhieh rises the standard 2 carrying the forwardly extending hollow work-supporting arm or horn 3 and the super posed bracket-arm .4 terminating in the hollow head 5 in which is journaled the re ciproeating needle-bar 6 carrying the eyepointed needles n 11 42 and W. The needle bar is actuated by means of the usual pitman connection 7 with the'crank-arm: 8 at the forward, end of the oscillatory needle-driving shaft 9 which extends within and length wise of the bracket-arm 1 and is connected, with the crank 10 upon the main-shaft 11 in any suitable manner.

Cooperating with the needles is the thread-carrying looper 12 which is mounted on'the looper-earrier 13. fixed to the forward end of the usual rocking and sliding shaft 14 extending lengthwise of and within the work supporting arm. 3. It will be understood that the shaft 14 is rocked to give the looper 12 the usual loop-seizingand shedding movements and is moved endwise to give the looper the usual sidewise or socalled needle-avoiding movements. Y

The machine is preferably equipped with the usual differential feeding mechanism including the fulling and main feed-dogs 15 and 16, respectively, and with suitable presser and covering thread mechanisms including the presser-foot 17 and covering thread fingers 18, all as more fully described in my said eopending application Serial No. 185,446. I

The present machine, like my said prior machine, is provided with a set of individual needle-thread controlling cams c c 0 and 0* which operate, respectively, upon the needle-threads 6 6 t and i Each of these cams preferably comprises two similar spaced disks formed as usual with a common hub. These'cams are'mounted on the camshaft 19 which is journaled in the threadcontroller frame 20 secured to'the top side of the bracket-arm l and is driven by a one-t-oone'bevel-gear connection 21 with the upper end of the inclined shaft 22 inclosed within the shaft casing 23. The lower end of the shaft 22 is connected to the mainshaft .11

stripper-plates 27 theformer serving in the usual manner to guide the needle-threads across the active peripheral portionof their .respective'cams .and the latter to cause the needle-threads to be deflected radially of said cams.

v Cooperating with the thread-controlling cams is a series of thread-nippers 28 which are more fullydescribed in mysaid eopendi'ng application and serve to lock the needlethreads While the needle-loops are being tightened after having been shed by the looper.

Mounted on top ofthe bracket-arm at the rear of the machine is the tension frame 29 carrying a plurality of tension devices 30 for the various sewing threads.

The needle-bar 6 is provided at its upper end with a multiple thread guide comprising a horizontal bar 31 having individual needlethread eyes 32. A bar or thread-stop 33, the

elevation of which is controlled by the thickness of the work as described in my said eopending application Serial No, 185,44t6, is provided to assist in measuring thread from the supply when the needle-bar approaches the upper end of its stroke. 7

All of the foregoing features of construetion'are present in my prior machine, as dis closed in my said eopending applications and, as has been stated, the take-ups or thread-controlling cams, under a given set of operating conditions, are so shaped as to control the needle threads with the required high degree of accuracy so that the machine will perform satisfactorily at high speed. The thread-control requirements, however, for a four-needle seam of the character made by the present machine, are so exacting that it'has not been found possible to design a set of average cams which will control the needle-loops with suflicient accuracyv under the various operating conditions met with in practice.

the points of the descending needles are about to pass their respective previously formed loops on the retracting looper-blade, and as the advancing looper is seizing the needle-loops.

In the particular embodiment of the invention chosen for the purpose of the present disclosure, the improvement comprises individual yielding thread-engaging devices (Z (Z (Z and 6Z which are associated in pairs with the supports 34 and 35. Each of the supports 34, 35 is in the form of an upstanding post having side surfaces 36 arranged in parallel vertical planes. The posts 3 1-, 35 are mounted at the top of the front side of the head 5 and extend upwardly from said head closely in rear oi the horizontal bar 31 of the thread-guiding bracket as shown in Fig. 3. The parallel side surfaces 36 of the posts 34, 35, are disposed. respectively, in planes substantially coincident with the vertical paths of movement of the thread-eyes 32 in the bar 31, so that, as the bar 31 reciprocates, the needle-thread lengths between the take-ups c to 0*, inclusive, and the thread-eyes 32 wipe over the respective surfaces 36.

The surfaces 36, of themselves, oiier no resistance to the free movement ofthe needle-thread either up and down or toward and from the needles. in order, however. to im pose a light yielding drag or thread absorbing action upon the needle-threads at certain periods of the stitch-forming cycle, the series of spring-fingers or yielding threadengaging devices (Z (Z (Z and (Z is provided. As these spring-fingers are similarly constructed and mounted on the pos s a description of one will sufice. Referring to Fig. 9, for example, the spring (Z is in the form of a flat blade, the shank of which is provided with a vertical slot 3'? through which passes the clamping screw 38 threaded into the post 35. A similar slot 39 is formed in the finger (i above the slot 37 to fit over the steady pin 40. This construction provides for vertical adjustment of the various fingers on their supporting posts.

From its lower end the spring (Z extends upwardly a certain distance to the offset il where it is bent inwardly into contact with the surface 36 of the post 35. From the oil?- set 41, the spring (5* extends upwardly in light contact with the surface 36 to the offset i2 where the spring is bent outwardly to clear the surface 36. From this point the spring extends upwardly to its reduced free end which is received between the guidi ears 43 on the post t is understood that the springs (Z (Z2 and (Z are constructed similarly to the spring (Z and are provided with the active thread-engaging portions between the oitset points or bends ll and 42.

Referring to Figs. at to 3, inclusive. it will be seen that the offsets 41 of the springs are arranged at progressively higher elevations beginning with the spring (Z While the offsets 42 are all arranged at substantially the same elevation. The purpose of this construction will be clear from the followingdescription of the operation of the machine.

Starting at the position shown 1n Figs. 8 and 12, with the needles up and the looper fully advanced, as the needles descend the looper begins its retracting stroke and the outwardly inclined portions of the cams 0 -4 at the left ofthe thread-guiding forks 26, Fig. 12, operate to absorb the needlethread given up by the descending threadeyes 32 in the bar 31 and prevent the formation of slack thread below the needles. l/Vhen the needle-points enter. the work, however, the thread-eyes 32 reach the position shown in Fig. 7 and carry their respective needlethreads below the inward bends 42 of the yielding three d-controlling fingers (l -d whereby said fingers impose a light drag or yielding thread absorbing action upon the respective downwardly-moving needlethreads by pressing them against the surfaces 36 of the posts 34, 35. This drag causes the needle-threads to be deflected more or less between the cams 0 -0 and the thread-eyes 32, thus absorbing a. little slack-thread and maintaining an even or uniform tension on each of the previous needleloops about the looper.

As the peaks a a a and a pass the vertical position or line of stationary threadeyes in the forks 26, the needle-threads #-25 are successively slackened as the respective needle-eyes descend below the work; the cams c"-c' being shaped in the present instance to afford a slight excess of slack thread which is absorbed by the yielding de vices (l -al It will be seen that the effect of these yielding devices is to' deflect the needle-threads upwardly between the takeups c 0 and the thread-eyes 32, as shown in Fig. l. A uniform strain is thus imposed upon the needle-threads at this time by the devices cZ cZ and this strain is substantially independent of the stitch-length as well as the thickness or character of the work being stitched. In other words the devices cZ -cZ impose a substantially uniform tension on the needle-threads during the descent of the needles regardless of variations in the amount of slack-thread which may make its appearance between the takeups c -c and thread-eyes 32 due to variations in sewing conditions. The more slack there is in the needle-threads, the greater will be the upward deflections imposed by the devices rZ cZ and vice *versa. The needle-loops on the retracting looper will thus be subjected to a uniform tensioning action under all conditions and will invariably assume evenly spaced positions, as shown in needles reach the end of their down stroke and the looper is fully retracted, Fig. 5, the cams c -c* have rotated 180. 7

As the needles rise they present their loops to the advancing looper; it being understood that the loops of the needles a a and a are suitably reduced in] size by their respective earns 0 and of prior to the seizure of such loops by the loo'per. One'of the chief causes I of, failure of machines of'the present charactor to perform satisfactorily is the tendency of the advancing looper to drag thepreviously seized needle-loop into a subsequently seized loop, whereby'certain of the needle-loops are crossed on the looper and cause malformed stitching if not thread breakage. In my prior machine, the individual rotary takeups were depended upon to maintain their respective needle-loops snugly about the looper-blade during its loop-seizing stroke. While these cams can, with care, be designed to accomplish this result satisfactorily, under a given set of operating conditions, it is found that variations in sewing conditions such as commonly met with in garment factories, introduce slight variations in the requirements for accurate thread-control, so that a given set of cams may not, of themselves, control the needle-threads with the high degree of accuracy required at this period of the stitch-forming cycle under variationsin operating conditions.

'For this reason the needle-thread controling devices (l -al are made use of to successively' tighten or snub the needle-loops about the looper-blade as the latter seizes said loops, so'that a previously seized needleloop cannot be dragged into a loop about to be seized. Referring to Fig. 6, it will be seen that the point of the advancing looper has entered well into the loop of needle n and. is-just entering the loopof needle a". At

his time the rising needle-bar 6 has carried the thread-eyes 32 as high as the inwardly directed bend l1 of the spring 03 whereupon further upward movement of the needle-bar will cause the thread 6 to be instantly tensioned by the spring al The loop of'the needle n will thus be brought under the yielding control of the spring al at the correct instant oftime and, it is evident,

that the spring al will maintain said loop lightly but snugly about the looper-blade and prevent it from bein dragged into th loop of needle 72?. V

,In a similar manner, the successively higher bends d1 of the springs 6Z2, (Z3 and (Z operate upon the threads 2?, t and tto successively tension the needle-loops during the advance of the looper. Variations in sewing conditions will have no appreciable effect upon the action of the devices el -al in controlling the needle-loops during their seizure by the looper for the reason that they are so designed and so related to the take-up eyes 32 as to come abruptly into action at the correct successive instants of time and to sud denly impose the desired light tension on the respective needle-loops regardless of whether the work be thick thin s rin 1 or 7 7 U relatively unyielding.

After the looper has reached the position shown in Fig. 7, the needle-threads are carried above the thread-engaging portions of the spring-fingers (ll-0F and further up; ward movement of the thread-eyes 32 serves to pull thread from the supply for'the next stitch. r

The thread-oontrolling devices may, if desired, be made up in the form shown in Fig. ll. In this form the post 45 is provided with otlsets L6 and 47 which are similar, respectively, to the oflsets {l1 and a2'ipreviously described; The springs is are doubled upon themselves at l and are secured at the lower ends of their outer limbs to the post 45. The inner limbs 48 of the springs bear lightly against the opposite side surfaces of the post between the offsets a6 and 47, as will be readily understood. The lower ends of the inner limbs 4L8 are freely received between guide wings 50. In this construction the springs exert a somewhat more nearly uniform pressure upon the needle -threads throughout their movement over the active length of the pressure exerting surfaces than is the case with the single springs.

While I shave shown and described one specific embodiment of the invention, it is to be understood that the invention is not limited to the specific form and arrangement of parts herein disclosed. Various modifications, substitutions, rearrangements, &c.,' may be readily made by one skilled in the art, in the light of the present disclosure, without departure from, or sacrifice of the advantages of the invention.

Having thus set forth the nature of the invention, what I claim herein is-' 1. A sewing machine having a plurality of needles set in a plane crossing the line of feed, a looper cooperatingtherewith to form stitches, means for tighteningthe needleloops as they are shed from the loo'per, and yielding means disposed out of engagement with the needle-threads at the beginning of the down-stroke of the needles and adapted to come into engagement with the needle threads as the needles descend and uniformly strain the needle-threads as the descending needle-points pass their respective previously formed loops 0n the looper.

2. A sewing machine having a plurality of needles set in a plane crossing the line of feed, a looper cooperating therewith to form stitches, means for tightening the needleloops as they are shed from the looper, and yielding devices disposed out of engagement with. the needle-threads when the needles are at the end of their down-stroke and adapted to engage the needle-threads as the needles rise and successively tighten the needlethread loops asthey are seized by the advancing looper.

3. A sewing machine having a needle-bar, a plurality of needles carried by said bar and set in a plane crossing the line of feed, a looper cooperating with said needles to form stitches, multiple thread guiding means carried by the needle-bar, take-up devices co operating with said thread guiding means for successively tightening the needle-loops as they are shed from the looper, and yielding thread deflectors disposed out of engagement with the needle-threads at the beginning of the down-stroke of the needles and adapted to come into engagement with the transversely moving needle-thread lengths extending between the take-up devices and the needle-bar to uniformly tension the needle-threads as the descending needlepoints are passing their respective previously formed loops on the loopen 4. A sewing machine having a needle-bar, a plurality of needles carried by said bar and set in a plane crossing the line of feed, a looper cooperating with said needles to form stitches, multiple thread guiding means carried by the needlebar, take-up devices co operating with said thread-guidingmeans fo successively tightening the needle-loops as they are shed fromthe looper, and yielding thread deflectors disposed out of engagement with the needle-threads when the needles are at the top and bottom of their strokes and arranged to act upon the transversely moving needle-thread lengths extending between the take-up devices and the needle-bar to uniformly tension the needle-threads as the descending needle-points are passing their respective previously formed loops on the looper, said deflectors being adapted to suecessively engage the needle-threads during the upward motion of the needle-bar to suecessively tighten the needle-loops as they are seized by the advancing looper.

5. A sewing machine having a reciprocating needle-bar, a plurality of needles carried by the needle-bar and set in a plane crossing the line of feed, a looper cooperating with the needles to form stitches, multiple thread guiding means on the need1e-bar,take-up means cooperatlng with sald thread-guiding means for successively tightening the needleloops as they are shed rrorn the looper, and a plurality of yielding thread engaging devices 1n addltion to the take-up means for iin JOSlIl a transverse wi in action u on the vertically moving portions of the needlethreads in rear 01 said multiple thread guiding means.

6. A sewing machine having a reciprocating needle-bar, a plurality of needles carried by the needle-bar and set in plane crossing loops as they are shed from the looper, and a plurality of yielding thread engaging devices disposed out of engagement with the needle-threads when the needles are at the lower end of their stroke, said devices being arranged each in the path. of movement of a respective needle-thread and adapted to act yieldingly and to successively tighten the needle-loops. as they are seized by the looper.

7. A sewing machine havinga plurality of needles set in a plane crossing the line of feed, a looper cooperating therewith to form stitches, threadhandling devices acting to move certain portions er the needle-threads transversely of the direction of their extent during the tightening of the previously formed needle-loops shed by the looper, and a plurality of yielding thread engagingdevices having coacting nipping surfaces, the planes or" which coincide respectively with the paths of transverse niovementof the noodle-threads; said devices being adapted to assume yielding control of the needlethreads the needle-points are passing their respective previously formed loops on the looper.

8. In a sewing machine, in combination, a plurality of needles, a looper, take-up means for reducing the sizes of certain'of the needle-loops prior to their seizure by the looper, and a plurality of yielding threadengaging devices out of engagement with the needle-threads during the first part of the Lip-stroke of the needles and adapted to successively tighten the needle-loops on the looper-blade during the loop-seizing stroke.

9; In a sewing machine, in combination, a plurality of needles, a looper, take-up means for reducing the sizes of certain of the needle-loops prior to their seizure by the looper, and a plurality of yielding thread engaging devices arranged out of contact with the needle-threads during the action of the take-up means in reducing said needle-loops, said devices having off-set portions arranged at different elevations so as to come successively into action and tighten the needle-loops as they are seized by the "looper.

10. Thread controlling mechanism for portions arranged at different elevations and adapted to come successively into action on the, needle-threads during the upward movement of the needle-bar.

yieldin thread controlling devicefor multiple needle single-looperi sewing ma-,

chines comprising, a post having spaced thread engaging surfaces at opposite sides thereof, and a plurality of yielding spring devices carried by said post and adapted to press against said surfaces, the opposed surfaces at one sideof the post being greater in active length than at the other side.

i 12. A yielding threadcontrolling device for sewing machinescomprising a post havinga thread-engaging surface, a spring having a pair of limbs extending side side and joined at their upper ends, the lower end of the outer limb of said spring being rlgid withsaid post and the inner limb of said spring being adapted to bear yieldingly against said thread-engaging surface.

13. A sewing machine havlng a plurality of reciprocating needles set in a plane cross ing the line of feed, a 'looper' coeperating therewith to form stitches, a set of individual'rotary cams for differentially controlling the needle-threads, and a set of in-f dividual yielding devices, arranged out of effective engagement with their respective needle-threads when the needles are at the pper and lower limits of their stroke and adapted to be successively engaged by the needle threads asthe corresponding needleloops are seized by the advancinglooper.

14. A sewlng machine having a plurality of needles set in a plane crossing the line of feed, a single .looper coeperating therewith to form stitches, a setiof tension devices,-a';

set of individual thread-cams adapted for differential control of the needle-threads, and a set of yielding needle-thread engaging devices operatively separated from sald cams, and disposed between the needles and the tensions.

15. A sewing machine having a plurality v of needles set in a plane crosslng the hue of feed, a single looper cooperating therewith to form stitches, means-including a set of individual rotary cams for successively tightening the needle-loops as they are shedby the looper, and a set ofyielding slacktnread controlling devices adapted to cooperate with said cams in successively and uniformly ti hten ng the needle-loops upon the looper-blade as they'are seizedby'the latter, regardless 'ofzvariations in sewing conditions. 7

16. Thread controlling multiple needle, single-looper sewing machines comprising, a plurality of threadcams adapted for differential control of the mechanism for needle-threads and a plurality of yieldingf slack thread controlling devices associated with said cams, substantially as and for the purposes specified. I V

17. A sewing machine having a plurality of needles set in a plane crossing the line of a feed, a single-looper cooperating therewith to form stitches, a plurality of individual thread-controlling cams adapted for differential control of the needle-threads, a plu rality of yielding thread engaging devices,

multiple thread guiding means associated with said thread-engaging devices, and means for relatively moving said, thread guiding means and device's transversely of the needle-threads, whereby to'secure a wiping action of the needle-threads over the v threadengaging surface portions or" the thread-engaging devices in directions transverse to the lead of the needle-threads.

In testimony whereof,' I have signed name to this specification.

enoaen s. eATonnLLQ i 

